At present, in live battlefield military operations in areas such as the Middle East, opposing forces using weapons such as the rocket-propelled-grenade (RPG) are presenting a significant threat to U.S. military forces stationed there. In an RPG weapon, a relatively small rocket charge is mounted in a tube, together with a grenade, which can then be aimed and launched at a target. One example of a commercially available RPG device is the RPG-7, which has been manufactured in a number of countries, including Russia and various Eastern European countries such as Romania, over its forty-plus year history. FIG. 1 is an illustration showing a prior art Russian-made RPG-7 antitank grenade launcher 2 (“RPG 2”). The RPG 2 is a recoilless, shoulder-fired, muzzle-loaded, reloadable weapon, capable of firing an 85-mm (PG-7) or 70-mm (PG-7M) rocket-assisted High Explosive Anti Tank (HEAT) grenade from a 40-mm smoothbore launcher tube. Features of the RPG 2 include a flared blast shield 3 (which also serves as the breech through which the charge can be loaded). The charge is provided to initially launch the grenade assembly from the firing tube. 3, a telescope optical sight 4, an iron sight 5, a heat shield 6 (which in this illustration is made of an insulating material such as wood), a trigger 7, a grenade 8, such as the PG-7VM grenade, and include a pair of hand grips 9A, 9B. The RPG 2 is light enough (around 15 pounds) to be carried and fired by one person.
With the RPG 2, launch of the grenade 8 is typically via a gunpowder booster charge (not visible in FIG. 1) at about 115 m/s, and this launch creates a cloud of light bluish grey smoke (which typically puffs out in the vicinity of the blast shield 3. It is the sight of this smoke that is often the only warning (i.e., a visual indicator) that a potential target has alerting the target that the RPG 2 has been fired. After the grenade 8 such as the 70 mm PG-7M is fired from the RPG 2, the PG-7M's internal rocket motor will ignite after the grenade 8 has traveled about 10-11 meters, giving the grenade 8 higher velocity, a relatively flat trajectory, and better accuracy. In addition, when the grenade round exits the tube of the RPG 2, several sets of fins 8A at the rear of the grenade round 8 unfold, to maintain direction and induce rotation. The maximum effective range of the RPG 2 is about 500 meters for stationary targets and 300 meters for moving targets, with a maximum overall range of about 920-1100 meters, at which point the grenade 8 will self destruct (typically about 4-5 seconds after it was launched). The fuse sets the maximum range of the grenade 8. One way the timed detonation of the RPG 2 has been used is to create rough proximity airbursts against targets such as helicopters once the targets have passed the preferred 100 meter “head-on attack” zone. In addition, some grenades used with the RPG 2 can penetrate armor up to 330 millimeters.
Although the RPG 2 generally won't travel as far as a larger rocket, the RPG 2 is far more portable (it can be held over a shoulder), lightweight, simple to use (literally “point and shoot”) and, unlike indirect weapons such as mortar, can be more directly aimed at a target, to produce damage essentially equivalent to a stick of dynamite detonated at the target location. Further, because the blast radius of anti-armor round fired by an RPG 2 is around 4 to 8 meters, personnel and/or equipment in proximity to an RPG blast will still experience significant negative effects from it. For example, personnel may experience effects such as temporary deafness and blindness from an RPG blast even if such persons are not permanently harmed or killed by the blast.
Because the RPG 2 is so simple to use, effective, damaging, and widely available, it has become the weapon of choice for many forces around the world, including many guerilla armies and insurgents hostile to U.S. interests. Consequently, the U.S. military has great interest in training its personnel to deal with military combat situations in which RPGs may be used.
One way that the U.S. military trains its forces to deal with various military combat situations is using laser-based combat simulation systems. Such laser-based systems have been developed to simulate military combat situations without actually having to fire live ammunition. These systems use relatively low power lasers and matched detectors for indicating when a “hit” has occurred. One such system is the Multiple Integrated Laser Engagement Systems, referred to as the MILES system. Military forces in the U.S. and around the world have found MILES to be an important tool to help soldiers and others learn combat survival skills and evaluate battle outcomes, and MILES training has been proven to dramatically increase the combat readiness and fighting effectiveness of military forces.
An illustrative implementation of MILES uses so-called eye-safe “laser bullets,” combined with the use of laser sensitive detectors, to simulate battlefield situations. Each individual and vehicle in the training exercise has a detection system to sense hits and perform casualty assessment. For example, as part of an exemplary MILES event, some soldiers are equipped with one or more laser detectors (e.g., an optical detector) capable of receiving a coded laser signal or pulse that has been fired, and these laser detectors can be attached to the soldier himself, to a vehicle the solder is riding on or in, or to any other location proximate to a target of interest. Other soldiers are equipped with laser transmitters capable of “shooting” coded laser signals and/or pulses of infrared energy. These laser transmitters can be readily attached to and detached from any location, person, or thing (e.g., vehicle mounted weapons, hand carried weapons, vehicles, tanks, etc.). In some implementations, one or more of the coded laser signals and/or pulses are modulated to indicate the type of weapon that is the source of the laser beam; and a soldier identification number may also be included in the transmitted signal.
When the laser sensitive detectors receive the coded laser signal/pulse(s), one or more MILES decoders determine whether the target was hit and, if so, whether the “laser bullet” was accurate enough to cause damage (e.g., a casualty). This determination can be made in various ways, such as by whether the coded signals/pulses exceed a threshold, whether the coded signals/pulses actually hit its intended target, and the like. In some implementations, the target (and/or the shooter) can be made aware almost instantly of the accuracy of a simulated shot, such as by audible alarms, visible displays, pyrotechnics, and the like, where these indicators can designate a hit or near miss and also help to provide realism for the soldiers.
In more recent implementations of MILES, all action by shooters and targets (deemed “players”) is recorded during a simulated event, so that a so-called After Action Review (AAR) can occur later, to review the effectiveness of the weapons and/or of the defenses against them. For example, one implementation of AAR allows commanders to process, format and view engagement data collected during an exercise, for review after the exercise. In addition, exercise data can be archived for future use, such as to provide additional training for military forces.